Shyam Kanjee, Roser Tetas

Royal Veterinary College, London, United Kingdom

Objectives

To evaluate epithelial healing time and complication rates following photoactivated chromophore for infectious keratitis–corneal cross-linking (PACK-CXL) in dogs with corneal ulcers, and to determine whether outcomes differ between brachycephalic and non-brachycephalic breeds.

Methods

A retrospective review of anonymised clinical records from a UK referral hospital (April 2020–September 2024) was performed. Dogs treated with PACK-CXL for naturally occurring corneal ulcers were included if complete follow-up to fluorescein stain negativity was available. Breeds were categorised as brachycephalic or non-brachycephalic. Data collected included signalment, ulcer depth, infection status, uveitis score, concurrent ocular disease, epithelial healing time and complications. Kaplan–Meier survival analysis compared time to re-epithelialisation between groups. Cox proportional hazards modelling assessed associations between healing time and age, uveitis score and ulcer depth. Statistical significance was set at p < 0.05.

Results

Forty-four dogs met the inclusion criteria (31 brachycephalic, 13 non-brachycephalic). Median epithelial healing time was 22 days in brachycephalic dogs and 36 days in non-brachycephalic dogs. This difference was not statistically significant (p = 0.3798). Ulcer depth, age and uveitis score were not significant predictors of healing time in multivariable analysis. Complications occurred in 22.7% of cases, including enucleation or surgical intervention, with no significant difference between groups (p = 0.449).

Statement: Impact/ Clinical Significance

PACK-CXL demonstrated comparable healing outcomes in brachycephalic and non-brachycephalic dogs. These findings suggest that skull conformation alone should not preclude consideration of this therapy, supporting its use as an adjunctive treatment for canine corneal ulcers in both primary care and referral practice.